Package structure and method for manufacturing the same

ABSTRACT

A package structure and a method for manufacturing a package structure are provided. The package structure includes a substrate, at least one redistribution structure, at least one electronic component and at least one semiconductor die. The substrate has a first surface and a second surface opposite to the first surface. The at least one redistribution structure is disposed on the first surface of the substrate. The at least one electronic component is disposed on the first surface of the substrate. The at least one semiconductor die is disposed on the at least one redistribution structure and electrically connected to the at least one electronic component through the substrate.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No. 16/862,453 filed Apr. 29, 2020, the contents of which is incorporated herein by reference in its entirety.

BACKGROUND 1. Field of the Disclosure

The present disclosure relates to a package structure and a manufacturing method, and to a package structure including at least one semiconductor die electrically connected to at least one electronic component through a substrate, and a method for manufacturing the package structure.

2. Description of the Related Art

A semiconductor package structure may include an active semiconductor die and electronic components (e.g., passive components). The electrical connection path from the active semiconductor die to the electronic components may be long, which may result in greater signal loss. The longer electrical connection path may adversely affect the electrical properties of the semiconductor package structure. To reduce the signal loss, the electrical connection path should be shortened.

SUMMARY

In some embodiments, a package structure includes a substrate, at least one redistribution structure, at least one electronic component and at least one semiconductor die. The substrate has a first surface and a second surface opposite to the first surface. The at least one redistribution structure is disposed on the first surface of the substrate. The at least one electronic component is disposed on the first surface of the substrate. The at least one semiconductor die is disposed on the at least one redistribution structure and electrically connected to the at least one electronic component through the substrate.

In some embodiments, a package structure includes a substrate, a redistribution structure, and a plurality of electronic components. The substrate has a first surface and a second surface opposite to the first surface. The redistribution structure is disposed on the first surface of the substrate. An area of the redistribution structure is smaller than an area of the substrate from a top view. The plurality of electronic components are disposed on the first surface of the substrate and electrically connected to the substrate.

In some embodiments, a method for manufacturing a package structure includes: (a) providing a substrate having a first surface and a second surface opposite to the first surface, wherein the substrate includes at least one conductive pad; (b) attaching a bonding layer on a redistribution structure; and (c) attaching the redistribution structure on the at least one conductive pad of the substrate by the bonding layer.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of some embodiments of the present disclosure are readily understood from the following detailed description when read with the accompanying figures. It is noted that various structures may not be drawn to scale, and dimensions of the various structures may be arbitrarily increased or reduced for clarity of discussion.

FIG. 1 illustrates a cross-sectional view of a package structure according to some embodiments of the present disclosure.

FIG. 2A illustrates a top view of an example of a package structure according to some embodiments of the present disclosure.

FIG. 2B illustrates a top view of another example of a package structure according to some embodiments of the present disclosure.

FIG. 2C illustrates a top view of another example of a package structure according to some embodiments of the present disclosure.

FIG. 3 illustrates a cross-sectional view of a package structure according to some embodiments of the present disclosure.

FIG. 4 illustrates a cross-sectional view of a package structure according to some embodiments of the present disclosure.

FIG. 5 illustrates a cross-sectional view of a package structure according to some embodiments of the present disclosure.

FIG. 6 illustrates a cross-sectional view of a package structure according to some embodiments of the present disclosure.

FIG. 7A illustrates one or more stages of an example of a method for manufacturing a package structure according to some embodiments of the present disclosure.

FIG. 7B illustrates one or more stages of an example of a method for manufacturing a package structure according to some embodiments of the present disclosure.

FIG. 7C illustrates one or more stages of an example of a method for manufacturing a package structure according to some embodiments of the present disclosure.

FIG. 7D illustrates one or more stages of an example of a method for manufacturing a package structure according to some embodiments of the present disclosure.

DETAILED DESCRIPTION

Common reference numerals are used throughout the drawings and the detailed description to indicate the same or similar components. Embodiments of the present disclosure will be readily understood from the following detailed description taken in conjunction with the accompanying drawings.

The following disclosure provides many different embodiments, or examples, for implementing different features of the provided subject matter. Specific examples of components and arrangements are described below to explain certain aspects of the present disclosure. These are, of course, merely examples and are not intended to be limiting. For example, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed or disposed in direct contact, and may also include embodiments in which additional features may be formed or disposed between the first and second features, such that the first and second features may not be in direct contact. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.

The present disclosure provides a new package structure. The package structure includes at least one redistribution structure and at least one electronic component disposed on a first surface of a substrate. At least one semiconductor die is disposed on the at least one redistribution structure and electrically connected to the at least one electronic component through the substrate. The electrical path from the electronic component to the semiconductor die through the substrate may be shortened. The shortened electrical path may reduce the signal loss and improve the electrical performance.

FIG. 1 illustrates a cross-sectional view of a package structure 1 according to some embodiments of the present disclosure. The package structure 1 includes substrate 10, a redistribution structure 30, at least one first conductive via 901, at least one second conductive via 902, at least one electronic component 70, at least one semiconductor die (including, for example, a fist semiconductor die 20 and a second semiconductor die 22).

In some embodiments, the substrate 10 includes at least one dielectric layer (including, for example, one first upper dielectric layer 13, one second upper dielectric layer 14, one first lower dielectric layer 11 and one second lower dielectric layer 16) and at least one circuit layer (including, for example, one first upper circuit layer 808, one second upper circuit layer 803 and one lower circuit layer 809 formed of a metal, a metal alloy, or other conductive material) in contact with the dielectric layer (e.g., the one first upper dielectric layer 13 and the first lower dielectric layer 11). In some embodiments, the second upper circuit layer 803 may be conductive pads.

In some embodiments, the substrate 10 may be similar to a core substrate that further includes a core portion 12, and may be in a wafer type, a panel type or a strip type. The substrate 10 may be also referred to as “a stacked structure” or “a low-density conductive structure” or “a low-density stacked structure”. The circuit layer (including, for example, the upper circuit layer 808 and the lower circuit layer 809) of the substrate 10 may be also referred to as “a low-density circuit layer”. As shown in FIG. 1 , the substrate 10 has a first surface 101 (e.g., a top surface) and a second surface 102 (e.g., a bottom surface) opposite to the first surface 101.

In some embodiments, the substrate 10 may include at least one inner via (including, for example, a plurality of interconnection vias 801, a plurality of upper interconnection vias 806 and a plurality of lower interconnection vias 807) formed of a metal, a metal alloy, or other conductive material.

The core portion 12 has a top surface and a bottom surface opposite to the top surface. The first upper circuit layers 808, the second upper circuit layer 803, the first upper dielectric layer 13 and the second upper dielectric layer 14 may be disposed on the top surface of the core portion 12. The second upper circuit layer 803 may include at least one conductive pad. Further, the lower circuit layers 809, the first lower dielectric layer 11 and the second lower dielectric layer 16 may be disposed on the bottom surface of the core portion 12. The interconnection vias 801 may extend through the core portion 12 and electrically connect the first upper circuit layer 808 and the lower circuit layer 809. Some of the upper interconnection vias 806 may be disposed between two first upper circuit layers 808 for electrically connecting the first upper circuit layers 808. Some of the upper interconnection vias 806 may be disposed between the first upper circuit layers 808 and the second upper circuit layer 803 for electrically connecting the first upper circuit layers 808 and the second upper circuit layer 803. In addition, some of the lower interconnection vias 807 may be disposed between two lower circuit layers 809 for electrically connecting the lower circuit layers 809.

In some embodiments, a material of the core portion 12 may include a bismaleimide triazine (BT) resin with a reinforcement material such as glass fiber. The first upper circuit layers 808 may be embedded in the first upper dielectric layers 13. The second upper circuit layer 803 may be disposed on the first upper dielectric layers 13. The second upper dielectric layer 14 may contact the second upper circuit layer 803. Further, the lower circuit layers 809 may be embedded in the first lower dielectric layers 11. The second lower dielectric layer 16 may contact the bottommost lower circuit layers 809. Materials of the first upper dielectric layers 13 and the first lower dielectric layers 11 may be, for example, polypropylene (PP) or ajinomoto build-up film (ABF). In some embodiments, a plurality of fibers (e.g., glass fibers) may be embedded in the first upper dielectric layers 13 and the first lower dielectric layers 11 to improve the material strength of the first upper dielectric layers 13 and the first lower dielectric layers 11. In some embodiments, the second upper dielectric layer 14 and the second lower dielectric layer 16 may be solder mask layers.

The redistribution structure 30 is disposed on the first surface 101 of the substrate 10. The redistribution structure 30 is attached to the substrate 10 through the bonding layer 40. The bonding layer 40 is interposed between the redistribution structure 30 and the substrate 10 to bond the redistribution structure 30 and the substrate 10 together. The bonding layer 40 may be cured from an adhesive material. The bonding layer 40 covers at least one conductive pad of the second upper circuit layer 803 of the substrate 10. The redistribution structure 30 is electrically connected to the substrate 10 through at least one first conductive via 901 and/or at least one second conductive via 902. The first conductive via 901 and the second conductive via 902 extend through the bonding layer 40 and a portion of the redistribution structure 30.

The redistribution structure 30 includes at least one dielectric layer 305 and at least one circuit layer 306 (formed of a metal, a metal alloy, or other conductive material) in contact with or embedded in the dielectric layer 305. In some embodiments, the redistribution structure 30 may be similar to a coreless substrate, and may be in a wafer type, a panel type or a strip type. The redistribution structure 30 may be also referred to as “a stacked structure” or “a high-density conductive structure” or “a high-density stacked structure”. The circuit layer (including, for example, the circuit layer 306) of the redistribution structure 30 may be also referred to as “a high-density circuit layer”. In some embodiments, a density of a circuit line (including, for example, a trace or a pad) of the high-density circuit layer is greater than a density of a circuit line of a low-density circuit layer. That is, the count of the circuit line (including, for example, a trace or a pad) in a unit area of the high-density circuit layer is greater than the count of the circuit line in an equal unit area of the low-density circuit layer, such as about 1.2 times or greater, about 1.5 times or greater, or about 2 times or greater. Alternatively, or in combination, a line width/line space (L/S) of the high-density circuit layer is less than a L/S of the low-density circuit layer, such as about 90% or less, about 50% or less, or about 20% or less. Further, the conductive structure that includes the high-density circuit layer may be designated as the “high-density conductive structure”, and the conductive structure that includes the low-density circuit layer may be designated as a “low-density conductive structure.

In some embodiments, a portion of the first surface 101 of the substrate 10 is exposed from the redistribution structure 30 from a top view. In some embodiments, a lateral side surface 303 of the redistribution structure 30 is recessed from a lateral side surface of the substrate 10 to form a step structure 103 for at least one electronic component 70 to be disposed. In some embodiments, the lateral side surface 303 of the redistribution structure 30 may substantially contact a lateral side surface of the electronic component 70. In some embodiments, the lateral side surface 303 of the redistribution structure 30 is substantially coplanar with a lateral side surface 20 s of the first semiconductor die 20 or the second semiconductor die 22. The redistribution structure 30 electrically connects the first semiconductor die 20 and the second semiconductor die 22 to the substrate 10.

In some embodiments, the at least one first conductive via 901 and the at least one second conductive via 902 extend through the redistribution structure 30 (including the dielectric layer 305 and the circuit layer 306). The first conductive via 901 and the second conductive via 902 are formed of a metal, a metal alloy, or other conductive material. In some embodiments, the diameter of the first conductive via 901 is about 60 μm (micrometers) and the diameter of the second conductive via 902 is less than 30 μm. A diameter of the first conductive via 901 is greater than a diameter of the second conductive via 902. The first conductive via 901 is nearer the electronic components 70 than the second conductive via 902.

In comparing with the second conductive via 902, the relatively greater diameter of the first conductive via 901 may accomplish a transmission of a large amount of signal. In addition, since the conductive via 901 is nearer the electronic component 70, the signal transmission path between the semiconductor die (e.g., the first semiconductor die 20 and the second semiconductor die) and the electronic component 70 through the conductive via 901 is shortened, which may reduce signal loss. Thus, the signal transmission path through the first conductive via 901 has less signal loss than through the second conductive via 902.

The electronic components 70 are disposed on the surface 101 of the substrate 10. The electronic component 70 may be a passive component. The electronic components 70 and the redistribution structure 30 are disposed side by side. The electronic components 70 may contact and may be electrically connected to the conductive pad of the second upper circuit layer 803 of the substrate 10. At least one of the electronic components 70 may be electrically connected to the first semiconductor die 20 and the second semiconductor die 22 through the second upper circuit layer 803 and the first conductive vias 901.

The first semiconductor die 20 and the second semiconductor die 22 are disposed on the redistribution structure 30. The first semiconductor die 20 and the second semiconductor die 22 are electrically connected to the at least one electronic component 70 through the substrate 10. In some embodiments, the first semiconductor die 20 and/or the second semiconductor die 22 may be electrically connected to the electronic component(s) 70 through the conductive bumps 95, the surface finish layers 96, the first conductive via 901 and the second upper circuit layer 803 of the substrate 10. The conductive bumps 95 may include solder material.

FIG. 2A illustrates a top view of an example of a package structure 1 a according to some embodiments of the present disclosure. The redistribution structure 30 is disposed on the first surface 101 of the substrate 10. The semiconductor dice 20 and 22 are disposed on the redistribution structure 30. An area of the redistribution structure 30 is smaller than an area of the substrate 10 from a top view. The plurality of electronic components 70 are disposed on the first surface 101 of the substrate 10 and electrically connected to the substrate 10. In some embodiments, a projection of the redistribution structure 30 falls on the substrate 10. The projection of the redistribution structure 30 falls within the area of the surface 101 of the substrate 10. The plurality of electronic components 70 surround the redistribution structure 30. In some embodiments, a ratio of an area of the redistribution structure 30 to an area of the substrate 10 is in a range of one third to one half.

FIG. 2B illustrates a top view of another example of a package structure 1 b according to some embodiments of the present disclosure. There are four semiconductor dice 23 disposed on the redistribution structure 30. In some embodiments, the number of the semiconductor dice may not be limited.

FIG. 2C illustrates a top view of another example of a package structure 1 c according to some embodiments of the present disclosure. The redistribution structure 30 may define an accommodating space 304 for accommodating a plurality of electronic components 70 from a top view. In some embodiments, the accommodating space 304 may accommodate at least one electronic component 70 from a top view. As shown in FIG. 2C, the redistribution structure 30 may be in an L-shape.

FIG. 3 illustrates a cross-sectional view of a package structure 3 according to some embodiments of the present disclosure. The package structure 3 is similar to the package structure 1 shown in FIG. 1 , except that the second upper dielectric layer 14 covers the second upper circuit layer 803. The first conductive via 901 and the second conductive via 902 are electrically connected to the second upper circuit layer 803 and extend through the bonding layer 40 and the second upper dielectric layer 14. In some embodiments, the second upper dielectric layer 14 may define a plurality of openings to expose portions of the second upper circuit layer 803. A portion of the bonding layer 40 may extend into the openings of the second upper dielectric layer 14. The first conductive via 901 and the second conductive via 902 may extend through the openings of the second upper dielectric layer 14. A portion of the bonding layer 40 may surround a portion of the first conductive via 901 and the second conductive via 902 in the openings of the second upper dielectric layer 14.

FIG. 4 illustrates a cross-sectional view of a package structure 4 according to some embodiments of the present disclosure. The package structure 4 is similar to the package structure 1 shown in FIG. 1 , except that there are two redistribution structures (including, for example, a first redistribution structure 31 and a second redistribution structure 32) disposed on the substrate 10. The two redistribution structures (e.g., the first redistribution structure 31 and the second redistribution structure 32) are separated by the electronic component 70. The electronic component 70 is disposed between the two redistribution structures 30. The first semiconductor die 20 is disposed on the first redistribution structure 31, and the second semiconductor die 22 is disposed on the second redistribution structures 32. In some embodiments, the electronic component 70 is disposed between the first redistribution structure 31 and the second redistribution structure 32. Thus, the electronic component 70 is disposed between the first semiconductor die 20 and the second semiconductor die 22.

FIG. 5 illustrates a cross-sectional view of a package structure 5 according to some embodiments of the present disclosure. The package structure 5 is similar to the package structure 4 shown in FIG. 4 , except that the electronic component 70 disposed between the first redistribution structure 31 and the second redistribution structure 32 is replaced by a dielectric layer 17. The dielectric layer 17 is disposed on the substrate 10. The lateral surfaces of the two redistribution structures (e.g., the first redistribution structure 31 and the second redistribution structure 32) contact the dielectric layer 17. The dielectric layer 17 may cover a lateral surface of the first redistribution structure 31 and a lateral surface of the second redistribution structure 32. In some embodiments, the dielectric layer 17 completely encapsulates the two redistribution structures (e.g., the first redistribution structure 31 and the second redistribution structure 32) (not shown).

FIG. 6 illustrates a cross-sectional view of a package structure 6 according to some embodiments of the present disclosure. The package structure 6 is a comparative embodiment. The package structure 6 is similar to the package structure 1 shown in FIG. 1 , except that the electronic components 70 are disposed on the redistribution structure 30. The electronic components 70 contact the surface finish layer 96. The electronic components 70 are electrically connected to the substrate 10 through the surface finish layer 96, the conductive via and the second upper circuit layer 803. The longer signal transmission path from the semiconductor dice 20, 22 to the electronic components 70 may result in greater signal loss.

FIGS. 7A, 7B, 7C and 7D illustrate a method for manufacturing a package structure according to some embodiments of the present disclosure. In some embodiments, the method is for manufacturing the package structure 1 shown in FIG. 1 .

Referring to FIG. 7A, a redistribution structure 30 is provided. The redistribution structure 30 of FIG. 7A may be similar to the redistribution structure 30 of FIG. 1 . The redistribution structure 30 includes at least one dielectric layer 305 and at least one circuit layer 306. Then, a bonding layer 40 is provided. The bonding layer 40 may be an adhesive layer. The bonding layer 40 is attached on the bottom surface of the redistribution structure 30. The bonding layer 40 covers a portion of the circuit layer 306.

Referring to FIG. 7B, a substrate 10 is provided. The substrate 10 of FIG. 7B may be similar to the substrate 10 of FIG. 1 . The substrate 10 includes at least one dielectric layer (including, for example, one first upper dielectric layer 13, one second upper dielectric layer 14, one first lower dielectric layer 11 and one second lower dielectric layer 16) and at least one circuit layer (including, for example, one first upper circuit layer 808, one second upper circuit layer 803 and one lower circuit layer 809) The second upper circuit layer 803 may include at least one conductive pad. In addition, the substrate 10 has a first surface 101 (e.g., a top surface) and a second surface 102 (e.g., a bottom surface) opposite to the first surface 101.

In some embodiments, the bonding layer 40 may be bonded on the substrate 10 firstly. Next, the redistribution structure 30 is attached on the bonding layer 40. Since an upper surface of the second upper circuit layer 803 may have slight height variation, the upper surface of the bonding layer 40 (the surface being contact with the redistribution structure 30) may be not non-planar, resulting in the risk of the void residue after bonding the redistribution structure 30. To address such concern, in a comparative embodiment, the bonding layer 40 may be thickened and the total thickness of the package structure 1 is increased. The size of the vias 901 formed subsequently may also be increased and the number of the I/O is reduced. Therefore, in the embodiment illustrated in FIG. 7B, attaching the bonding layer 40 to the redistribution structure 30 firstly is preferred, since the bottom surface of the redistribution structure 30 (including the surface of the dielectric layer and the pads of the redistribution structure 30) has a preferable overall flatness. After attaching the bonding layer 40 to the redistribution structure 30, the redistribution structure 30 and the bonding layer 40 are together bonded to the substrate 10. Since the redistribution structure 30 is a unit element, the pressure of bonding the redistribution structure 30 to the second upper circuit layer 803 is greater than the pressure of disposing the bonding layer 40 to the second upper circuit layer 803, so that the second upper circuit layer 803 is easily embedded in the bonding layer 40 and the void between the second upper circuit layer 803 and the bonding layer 40 may be relatively avoided. This arrangement may prevent the void in the bonding layer 40.

Referring to FIG. 7C, the redistribution structure 30 is attached to the substrate 10 through the bonding layer 40. The redistribution structure 30 is attached on the conductive pad of the second upper circuit layer 803 of the substrate 10 by the bonding layer 40. The bonding layer 40 covers the conductive pad of the second upper circuit layer 803. In some embodiments, a portion of the surface 101 of the substrate 10 is exposed from the redistribution structure 30 from a top view. Then, a plurality of first conductive vias 901 and a plurality of second conductive vias 902 are formed to extend through the redistribution structure 30 and the bonding layer 40. The first conductive vias 901 and the second conductive vias 902 contact the conductive pad of the second upper circuit layer 803. Then, the surface finish layers 96 are formed on the first conductive vias 901 and the second conductive vias 902.

Referring to FIG. 7D, a plurality of electronic components 70 are attached on the surface 101 of the substrate 10 to electrically connect the second upper circuit layer 803 of the substrate 10. Then, two semiconductor dice (e.g., a first semiconductor die 20 and a second semiconductor die 22) are provided and attached to the surface finish layers 96 by the conductive bumps 95. Thus, the semiconductor dice (e.g., the first semiconductor die 20 and the second semiconductor die 22) are electrically connected to the first conductive vias 901 and the second conductive vias 902. Therefore, the package structure 1 of FIG. 1 is obtained.

Spatial descriptions, such as “above,” “below,” “up,” “left,” “right,” “down,” “top,” “bottom,” “vertical,” “horizontal,” “side,” “higher,” “lower,” “upper,” “over,” “under,” and so forth, are indicated with respect to the orientation shown in the figures unless otherwise specified. It should be understood that the spatial descriptions used herein are for purposes of illustration only, and that practical implementations of the structures described herein can be spatially arranged in any orientation or manner, provided that the merits of embodiments of this disclosure are not deviated from by such an arrangement.

As used herein, the terms “approximately,” “substantially,” “substantial” and “about” are used to describe and account for small variations. When used in conjunction with an event or circumstance, the terms can refer to instances in which the event or circumstance occurs precisely as well as instances in which the event or circumstance occurs to a close approximation. For example, when used in conjunction with a numerical value, the terms can refer to a range of variation less than or equal to ±10% of that numerical value, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%. For example, a first numerical value can be deemed to be “substantially” the same or equal to a second numerical value if the first numerical value is within a range of variation of less than or equal to ±10% of the second numerical value, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%. For example, “substantially” perpendicular can refer to a range of angular variation relative to 90° that is less than or equal to ±10°, such as less than or equal to ±5°, less than or equal to ±4°, less than or equal to ±3°, less than or equal to ±2°, less than or equal to ±1°, less than or equal to ±0.5°, less than or equal to ±0.1°, or less than or equal to ±0.05°.

Two surfaces can be deemed to be coplanar or substantially coplanar if a displacement between the two surfaces is no greater than 5 μm, no greater than 2 μm, no greater than 1 μm, or no greater than 0.5 μm. A surface can be deemed to be substantially flat if a displacement between a highest point and a lowest point of the surface is no greater than 5 μm, no greater than 2 μm, no greater than 1 μm, or no greater than 0.5 μm.

As used herein, the singular terms “a,” “an,” and “the” may include plural referents unless the context clearly dictates otherwise.

As used herein, the terms “conductive,” “electrically conductive” and “electrical conductivity” refer to an ability to transport an electric current. Electrically conductive materials typically indicate those materials that exhibit little or no opposition to the flow of an electric current. One measure of electrical conductivity is Siemens per meter (S/m). Typically, an electrically conductive material is one having a conductivity greater than approximately 10⁴ S/m, such as at least 10⁵ S/m or at least 10⁶ S/m. The electrical conductivity of a material can sometimes vary with temperature. Unless otherwise specified, the electrical conductivity of a material is measured at room temperature.

Additionally, amounts, ratios, and other numerical values are sometimes presented herein in a range format. It is to be understood that such range format is used for convenience and brevity and should be understood flexibly to include numerical values explicitly specified as limits of a range, but also to include all individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly specified.

While the present disclosure has been described and illustrated with reference to specific embodiments thereof, these descriptions and illustrations are not limiting. It should be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the true spirit and scope of the present disclosure as defined by the appended claims. The illustrations may not be necessarily drawn to scale. There may be distinctions between the artistic renditions in the present disclosure and the actual apparatus due to manufacturing processes and tolerances. There may be other embodiments of the present disclosure which are not specifically illustrated. The specification and drawings are to be regarded as illustrative rather than restrictive. Modifications may be made to adapt a particular situation, material, composition of matter, method, or process to the objective, spirit and scope of the present disclosure. All such modifications are intended to be within the scope of the claims appended hereto. While the methods disclosed herein have been described with reference to particular operations performed in a particular order, it will be understood that these operations may be combined, sub-divided, or re-ordered to form an equivalent method without departing from the teachings of the present disclosure. Accordingly, unless specifically indicated herein, the order and grouping of the operations are not limitations of the present disclosure. 

What is claimed is:
 1. A package structure, comprising: a low-density conductive structure; a high-density conductive structure disposed over the low-density conductive structure; a bonding layer interposed between the high-density conductive structure and the low-density conductive structure; and a plurality of through vias extending through the high-density conductive structure and the bonding layer to electrically connect to the low-density conductive structure, wherein the plurality of through vias comprise a first through via having a first width and a second through via having a second width, and the first width is different from the second width.
 2. The package structure according to claim 1, wherein an interface between the first through via and the low-density conductive structure has a third width, and an interface between the second through via and the low-density conductive structure has a fourth width, wherein the third width is different from the fourth width.
 3. The package structure according to claim 1, wherein the high-density conductive structure defines a first opening exposing the first through via and a second opening exposing the second through via; and wherein a width of the first opening is different from a width of the second opening.
 4. The package structure according to claim 1, wherein a width of the first through via in the bonding layer is different from a width of the second through via in the bonding layer at a same elevation.
 5. The package structure according to claim 1, wherein a width of the first through via is greater than a width of the second through via; and wherein the first through via is closer to a lateral edge of the high-density conductive structure than the second through via is.
 6. The package structure according to claim 5, wherein the first through via and the second through via taper toward the low-density conductive structure.
 7. The package structure according to claim 1, wherein the first through via comprises a first portion disposed in the high-density conductive structure and a second portion disposed in the bonding layer; and wherein a lateral side surface of the first portion of the first through via is aligned with a lateral side surface of the second portion of the first through via.
 8. The package structure according to claim 7, wherein the second through via comprises a first portion disposed in the high-density conductive structure and a second portion disposed in the bonding layer; and wherein a lateral side surface of the first portion of the second through via is aligned with a lateral side surface of the second portion of the second through via.
 9. The package structure according to claim 1, wherein a length of at least one of the plurality of through vias is greater than a sum of a thickness of the high-density conductive structure and a thickness of the bonding layer.
 10. The package structure according to claim 1, wherein a width of the first through via is greater than a width of the second through via, and the package structure further comprises a plurality of electrical components disposed over the high-density conductive structure; wherein the second through via is closer to a gap between the plurality of electrical components than the first through via is.
 11. A package structure, comprising: a substrate; a redistribution structure spaced apart from the substrate by a space; a bonding layer disposed in the space and configured to bond the redistribution structure and the substrate; and a through via extending through the redistribution structure and the bonding layer to electrically connect to the substrate; wherein a width of the redistribution structure is less than a width of the substrate; wherein the through via comprises a first portion disposed in the redistribution structure and a second portion disposed in the bonding layer; wherein a lateral side surface of the first portion of the through via is aligned with a lateral side surface of the second portion of the through via.
 12. The package structure according to claim 11, wherein a sum of a thickness of the redistribution structure and a thickness of the bonding layer is less than a thickness of the substrate.
 13. The package structure according to claim 11, wherein a portion of an upper surface of the substrate is exposed from the redistribution structure.
 14. The package structure according to claim 13, wherein a width of the bonding layer is less than a width of the substrate.
 15. The package structure according to claim 14, wherein a lateral side surface of the bonding layer is not recessed from a lateral side surface of the redistribution structure.
 16. A package structure, comprising: a substrate having an upper surface; a first redistribution structure disposed over the upper surface of the substrate; a second redistribution structure disposed over the upper surface of the substrate and separated from the first redistribution structure; at least one first through via extending through the first redistribution structure and electrically connecting the first redistribution structure and the substrate; and at least one second through via extending through the second redistribution structure and electrically connecting the second redistribution structure and the substrate, wherein a width of the at least one first through via is different from a width of the at least one second through via.
 17. The package structure according to claim 16, wherein the first redistribution structure does not overlap the second redistribution structure in a direction perpendicular to the upper surface of the substrate.
 18. The package structure according to claim 16, wherein the at least one first through via comprises a plurality of first through vias; wherein the plurality of first through vias have different widths.
 19. The package structure according to claim 16, further comprising: a first bonding layer interposed between the first redistribution structure and the substrate, and configured to bond the first redistribution structure and the substrate; and a second bonding layer interposed between the second redistribution structure and the substrate, and configured to bond the second redistribution structure and the substrate; wherein the first bonding layer is separated from the second bonding layer.
 20. The package structure according to claim 16, further comprising a dielectric layer between the first redistribution structure and the second redistribution structure. 